Jam and Jelly problems?

Late spring is jam and jelly season at AnswerLine. We get lots of calls this time of year from folks wondering what went wrong. I’ve listed some of the more common problems and their causes for jam and jelly.

Sugar crystals in my jelly:

  • You may have used more sugar than the recipe listed.
  • There might have been undissolved grains of sugar on the sides of the pan that washed into the jelly while ladling into the jars.
  • Overcooking the jam or jelly by cooking too long.
  • Doubling or tripling the batch.
  • Crystals could be tartrate crystals—these are found in grape juice that has not been allowed to settle and strained.

Bubbles in my jelly:

  • Trapped air in the jelly—remember to skim foam before filling jars.
  • Fill jars quickly to prevent partial gelling before jars are filled.
  • Bubbles may be an indication of spoiling. If the bubbles are moving discard.

Jam or Jelly did not set:

  • You may have overcooked the fruit while extracting the juice or used too much water in this part of the process.
  • You may not have measured the ingredients accurately—or doubled the recipe.
  • You may not have cooked the jam or jelly quite long enough.
  • You may have moved the jam or jelly before it had a chance to set up in the jars.
  • Or, the jam or jelly may need several weeks to set up properly.

Jam or Jelly seems to be weeping:

  • There may be extra acid in the juice that made the pectin unstable.
  • You may be storing the jam or jelly in a place that is too warm.

My Jam or Jelly seems to be darker than I expected:

  • You may have boiled the jam or jelly too long or cooked it too slowly.
  • The jam or jelly may have been stored in a place that is too hot

My Jelly is cloudy:

  • You may have used fruit that is under ripe.
  • You may have squeezed the juice bag while straining the juice from the fruit. Just let the juice drip out next time.
  • You may have waited too long to place the jam or jelly in the jar. Ladle it into jars before it begins to set up.

My Jam or Jelly is too stiff:

  • You may have overcooked the jam or jelly.
  • The fruit you used may have too much pectin in it—remember to use ripe fruit.

Remember to call us for directions to remake jams or jellies that do not gel properly. We love to be able help.

Liz Meimann

I received both my undergraduate and graduate degrees in Food Science at Iowa State University. I love to quilt, sew, cook, and bake. I spent many years gardening, canning, and preserving food for my family when my children were at home.

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242 thoughts on “Jam and Jelly problems?

  1. Hi Karen, guava jam can be made with or without the skins depending upon your recipe. If you are making the jam without pectin, then the fruit and seeds are scooped out and prepared with just the pulp. If you are using pectin, then the top stem and the bottom nub are removed, cut into fourths, and cooked until the skins softened. Once soft, the mixture is blended and then sieved to remove the seeds before beginning the gelling process–adding sugar and pectin.

  2. My jelly set just fine. But it’s too sweet! Can I reheat it and add more unsweetened juice? Will it reset?

  3. Hi Sonja, since you don’t mention the kind of jelly you made or your recipe, my response will be ‘in general.’ If you reheat your jelly and add more juice, the jelly will not reset. The best scenario is to think of ways you can use it to sweeten other things such as plain yogurt, for example. If you do decide to reheat with added juice and the jelly does not set, you may want to take a look at Remaking Soft Jams and Jellies to determine what you may need to do with the jelly that doesn’t reset.

  4. Hi,
    I have a new toy, a hand blender. I tried using it when I made my jam. I used the blender as the jam was boiling. It seemed that the fruit blended and the mixture seems more like baby food rather than jam. The jam was boiling but didn’t get over 214 degrees.
    Should I expect it to set, or will it remain as baby food texture?

  5. Hi Ione, I’m guessing that you are making jam without pectin since you mention the temperature at 214 degrees. The jam is undercooked as for it to set it should reach 220 degrees. At this point, you can reheat and cook the jam until it reaches 220 degrees. At that point in time, it should be jam thick and be translucent in color. Do watch it very closely so that it doesn’t scorch.

  6. I made wild grape jam today and it is perfect. But I am reading comments about tartrate crystals and I did not let juice sit prior to canning. I do not have crystals but could they form over time? Or is this something you would notice right away? Thanks.

  7. Hi Toni, tartrate crystals may form in your jam as it sits. If they do form, they are harmless, just unwanted crunchy bits in the jam. As you already know, letting the juice sit for 24-48 hrs is the way to prevent them. My experience is that 48 or more hours is better than 24. Thank you for your question.

  8. I noticed I have a bit of water on my grape jelly, can I open the jars and dump the purple liquid and then heat it and reseal the jar?

  9. Hi Darlaine, The bit of water that you are seeing is likely due to condensation that dripped down from the top of your lid or it is syneresis or weeping. Neither is harmful and I would not advise reheating and reprocessing. If the jars have been water bathed properly and the lids are sealed, they are safe to consume. Weeping happens when the pH of the fruit is a little to acidic for the pectin that was used.

  10. Purchased fresh concord grapes this fall, ran thru a processor to remove seeds and skins. Made some jelly and ran out of time so I put into my kettle and stuck into extra fridge. Went to make jelly or juice and found a large amount of mold and sediment on top of the juice. No sugar or anything added. Is it ok to skin off the top, run thru a filter (coffee) and make jelly out of the juice? Does taste pretty good and I am not a wine drinker. Just hate to waste all the juice but Covid-19 hit and I was working 29/30 days,


  11. Hi Debbie, You will want to just throw it away. Mold sends unseen roots or tendrils down throughout soft or liquid food items in addition to the fuzzy growth. Additionally, some molds produce mycotoxins that have negative health effects. Some toxins produced by microorganisms are heat stable. Therefore I do not feel that it would be safe for you to just boil it and make it into jam. In the future, you will want to make your jam/jelly as soon as possible after juicing it or freeze it until you can get to it for the best quality. I’m sorry life got in the way of your best intentions.

  12. The foam on top of the jelly after cooking is settling into the jelly making it hard to remove. I am following the directions carefully, but can’t figure out what I am doing wrong. The jelly is mayhaw. Any suggestions?

  13. Hi Trudy, there is a lot of air in jams and jellies and boiling them hard to get them to set properly only makes it more so. The best way to knock the foam down is to add a teaspoon of butter or olive oil at the end of the cooking cycle to the jam, stirring it in; fat is an enemy of foam. Then use a spoon to skim off any foam that remains the best that you can. What you can’t get off or that sinks into the jam can be stirred into the jam before putting the jam in the jars. Foam is not harmful but may be a little unsightly to some. The foam that is taken off can be cooled and then carefully reheated in a microwave for a few seconds to bring it back to jam- or jelly-like consistency.

  14. I made strawberry jam, following all directions except left too much headspace, closer to 1/2″. They did seal well. Is that enough to make it shelf stable? Or should I be concerned? 1st time canner here.

  15. Trina, we all learn from our mistakes and in this case, while 1/4-inch headspace would be best, you should be fine with a slightly larger headspace. If you were going to make a mistake, having it happen with jam is the most forgiving. Headspace is about having the proper space to get a good seal. When headspace is incorrect, it can prevent you from getting a good seal. Or, improper headspace can result in seal failure on the shelf which might cause a food safety issue. Seal failure may also cause discoloration of the product; discoloration is not a food safety issue but certainly can be unsightly. You’ve indicated that you have a good seal so put the jars on your shelf and watch them carefully; likely all will be well. In the future, make every attempt to get the headspace right. So glad you gave canning a try!

  16. I made a red wine blueberry jam that didn’t set well. It’s delicious but kinda runny and loose. Any ideas on how I can fix that in the future?

  17. My Blackberry freezer jam has a light purple butter looking substance throughout the jars. It’s been in the freezer for a year.
    Do you know what it is?

  18. Hi Dana, the substance you are seeing could be any number of things all of which are benign when it comes to food safety if the jam was prepared properly a year ago. Most freezer jams do well in the freezer for up to a year and after that the quality begins to deteriorate slowly over time. Again, all of these issues do not render the jam unsafe as all are quality issues, not food safety issues. If you used pectin, it may be that the sugar and pectin did not dissove completely and crystals have formed while in the freezer; it is sometimes difficult to get the sugar to dissove completely with freezer jams and if the sugar does not dissove completely, the pectin doesn’t always thicken as it should. There is a very good chance that once the jam is thawed and stirred, the substance will disappear.

  19. I came across this website because recently I have canned blueberries using a simple syrup. I followed a specific recipe and did everything correctly but I noticed after about 4 days the top of the jars and the blueberries on top have tiny white spots on them, like they’re crystallized. Is this still safe to store or should I use them up now/ or dispose of? Thanks!

  20. Hi Shelby, I suspect those white spots are melted wax from the blueberries that melts at a temperature of at least 140°F. When canning fresh blueberries, the wax melted, then re-solidified during cooling leaving the little white rings. Reheating should melt it again. This is not harmful and is a natural component of the fruit.

  21. Hi
    I make a lot of jam in small batches. Many times I do a double batch without any problems. This time I forgot to double the pectin and of course the jam is soft and runny. SO I opened everything. Put it all in the pan and added more pectin. Cooked to the right temperature etc. but after one day letting it set – well it didn’t. So now is there any way I can save this jam??
    Thanks for your help
    Chris Bozak

  22. Hi Chris, I’m not sure that the jam is salvageable as a jam but perhaps as a syrup that can be used on ice cream, desserts, pancakes, and waffles, etc. The best publication I know on remaking soft Jams and Jellies, was prepared by Kayla Wells-Moses at Washington State. The link is below and may provide some additional insight that is helpful now or in the future should you have a similar experience. https://s3.wp.wsu.edu/uploads/sites/2053/2021/06/Remaking-Soft-Jams-and-Jellies-FS253E.pdf

  23. Hello,
    Just made strawberry mango jam. I did take a spoon out to look for consistency. It set very quickly. After canning in a hot water bath, some of my jars set and some are slightly runny. I did use a couple different kinds of jars. The ball jelly jars are the ones that completely set. The other jars did not. Ball Square fancy jars… not sure what to call them.
    I’ve never had this happen before. I was wondering if they can be fixed.
    I’m an experienced canner and very confused about this.
    Thank you!

  24. I made raspberry freezer jam with low sugar Sure Gel. I let it sit in the glass jars with a Ball lid for 48 hours at room temp. I also left half an inch of space for expansion. I found that the jam had expanded over the top. It smells and tastes normal. Is it safe to use?

  25. Hi Ann, I’m not sure why the jam expanded as you indicate; expansion does happen in the freezer which is the reason that 1/2 inch of head space is recommended. The jam should have been refrigerated or frozen after 24 hrs. I hope that by now it has been stored properly. If the jam smells and tastes okay, it is probably safe; however, there is a good chance that any refrigerated jam will spoil before the recommended “use by” 3 weeks. Do watch it carefully. If you intend to freeze the jam, please use a plastic jam container as the glass jar is likely to crack–not from the cold but from the expansion.

  26. My grape jelly set up just fine. But I left some in my truck to long and the heat got to it.
    Will it set back up?

  27. Hi, There are two concerns – safety and resetting.

    Safety: If the jam was properly canned and is still sealed, it shouldn’t be spoiled. The temperatures in canning are supposed to kill bacteria. Exposure to more temperature shouldn’t make the jam unsafe to eat.

    Resetting: Pectin, which is found in fruit and acts as a thickener in many jams and jellies, denatures at high temperatures, which results in the thinner, liquid-like jelly you have. I would not recommend attempting to remake it. Rather, it can still be used as a compote, a syrup, or a sweetener in any situation (like baking, for example) where the precise thickness and/or texture doesn’t matter.

  28. Asking for my mom… She makes jellies, jams and syrups, but every once in a while she’ll have a whole batch spoil on the top layer in storage (like quickly, within a month or two, so not age spoilage). What could be causing this?

  29. Hi Nicole, you do not say what recipe source or processing method your mother is using. Further, is the reason for the spoilage because the lids do not stay sealed or is the product spoiling inside the vacuum sealed jar? If you could provide more info, it would be helpful to help solve or at least provide more insight into the problem.

  30. I made grape jelly yesterday from wild foraged grapes. But, the lids have not sealed on all of them and I don’t know why. Is there a way to reprocess it or should I just put them in the freezer? The jelly set perfectly.

  31. Jennifer, since you made the jelly yesterday, you are in a position to reprocess or freeze the jelly. Actually freezing would be the best route as often times jelly breaks down with reprocessing. Why the lids didn’t seal? Could be any of the following: poor quality lids, hairline crack in the jar rim, headspace incorrect, rim of jar not clean, band too tight or too loose, removing jars too quickly from water bath, not removing air bubbles (air can have the same effect as leaving too much headspace), tightening bands after removing jars from canner, or just plain bad luck.

  32. my jar of Amish-made lemon jelly has cloudy areas that are spreading. It was opened a couple weeks ago & refrigerated. Is it sae to eat? Can I re-cook it? It smells & tastes ok.

  33. Hi Andra, the reason that the lemon jelly is cloudy could be due to a variety of reasons; what surprises me most is that it apparently started out clear and has clouded since opening if I follow your question correctly. In general, cloudiness in homemade jelly is due to fruit that was green at the time of jelly making, some pulp was squeezed into the juice, or the jelly was not quickly poured into jars after jelling temperature was reached. If this is a commercial product, none of these causes should be an issue. Cloudy products are safe to eat unless there are moving bubbles or product appears spoiled.

  34. I’m making green tomato jam, and it smells horrible as it cooks in the crockpot—not a burned smell but like old socks smell, only so much more intense. I followed the recipe except I halved the lemon juice because I ran out of lemons and added a couple spoons of tart strawberry tea. Might that be the reason? Or did I burn it, and that’s how burned green tomatoes smell?

  35. Maria, green tomato jam should smell like the ingredients that are used to flavor it. Some recipes use lemon and ginger and others use flavored gelatin. If you scorched it, it will have a foul smell and taste. Green tomatoes themselves have an earthy smell, something like the leaves of the tomatoes or the smell that you get while picking tomatoes in the garden. As the tomatoes ripen, these odors are oxidized and no longer detectable in or on a ripe tomato.

  36. Hi, I made my first batch of grape juice and jelly yesterday. All six of the juice jars turned out great. All of the jelly jars (pint jars) sealed. I left 1/4″ headspace per the Sure-Jell low sugar instructions. However, when I unscrewed the rims and checked the seal some of the jars are sticky at the top under the rims. My guess is that some leaked out while canning? I canned them for 10 minutes in a boiling water bath. One jar fell over in the canner and I had to rescue it, but unfortunately I don’t know which jar it was. Also, two jars got boiled longer because I had the burner heating and it took longer than I expected to fill the last jar. Hopefully I’ll be more adept at the process next time.
    Are they okay to eat? Should I just wash off the outside? Thanks!

  37. Hi Kristine, Congratulations! It seems you have had a successful first try with jelly making and canning. It is not uncommon for some stickiness around the top of the jars; it is caused by some siphoning during processing and/or tipping the jars when taken out of the water. Perhaps next time, tighten your lids just a big more. Wash your jars and bands to remove the stickiness and keep your bands from rusting. All in all, your jelly is safe. I would suggest that you put the jar that tipped over in the water in the refrigerator and use it first. Even though it is sealed, a small amount of water may have gotten into the jelly which could cause molding. To prevent jars tipping in the future, you can place open jars filled with water to take up the space in the canner. Keep up the good work!

  38. Hello,
    I’m having problems when making Jalapeno jelly. It comes out tasting like ACV. I have followed the directions to a T and have now made two batches and both are not eatable due to the taste. Do you have any advise?

  39. Hi Sherri, I’ve no idea what recipe you might be using. We always encourage the use of tested recipes. I have personally used the recipe from the National Center for HOme Food Preservation, a trusted USDA source, and enjoy it. Check it out at: https://nchfp.uga.edu/how/can_07/golden_pepper_jelly.html It uses white vinegar rather than apple cider vinegar. Hopefully you will enjoy this recipe as much as I do over cream cheese or with meat.

  40. Here is another recipe for jalapeno jelly using white vinegar from Oregon State: chrome-extension://efaidnbmnnnibpcajpcglclefindmkaj/https://extension.oregonstate.edu/sites/default/files/documents/8836/sp50454preservingpeppers.pdf

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